I have a Trace Elliot RAH350SMX 700 watt bass amp, which I love to death, yet, the only thing that works currently is the preamp, cause it has no fuses atm, need to repair that.

Since it's a single channel amp(kinda) I'm wondering what the best 12AX7 style tube to put in the preamp(with this amp, the valve makes a HUGE difference in tone)?

I have an old worn out JJ in there from out of my Valveking, but I'm looking for a quicker clipping that's also smooth. Could I throw something like a 7025 in there? Or a 12AU7?
I have a Sovtek 12ax7 in my ashdown, clips fairly quickly.

That said, that distortion still sounds nowhere near as good as if I run my POD X3 into the front end and use one of its guitar amps paired with a bass amp.

But I'm very skeptical of the mojo of tubes.

But yeah, Sovtek 12ax7 should help? Other than that, I'd say if you're after a faster, dirtier breakup, avoid the more expensive gold-pin options, as they tend to be smoother, and may not give you the dirt you're after.
A 7025 is a 12AX7. 12AU7 is a low gain, low plate voltage tube, chances are it will curl up it's toes and die.
'Twer i you I'd go for a JJ 12AX7S. Those are the ones that are a replica of a Telefunken.
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